583846583846
目前許多射頻模組（RF module)所採用的架構是超外 f收發裝置，中頻段在數十到數百兆赫，幾乎多採用 牮波濾波器（surface acoustic wave filter saw)作為猫 率選擇遽、波ϋ。 乍為頻 Λ目前射頻積體電路（RF IC)，第一次降頻混波器大多 採用差動開集極方式輸出，但是第二次降頻大多採用單端 輸^，導致信號除了要雙端轉單端外，還要考慮中間與表 面聲波濾波器的連接效應。 ”又 第1圖表示習知轉換介接電路。前端電路100包含一低 雜訊放大器1 1 〇，一混波器丨2 0，其輸出端丨A、丨B為差動開 集極。需要一轉換介接電路50將差動信號轉換到單端信汗 號，其包括電阻R1、電感L1、電容C1、電感L10、電容° C10、電容C20。轉換介接電路50輸出單端信號到表面聲波 濾波器40的輸入端。電感L1、電容C1調諧在所需要的中頻 段’並且在輸出端ΙΑ、IB提供180度反相輸出，結合同相 能量’輸入單端負載，也就是轉換介接電路5〇的功能為電 流結合器（current combiner)。電感L1 0是用以輛流 (choke)中頻（if)信號進入VCC，並且有另一功能是配合 電容C20作為匹配電路，電容C20功能為再抑制中頻信號°^ 入vcc所產生的信號干擾。電容cio作為直流隔離（DC儿貝 blocking)。另一方面，電容C10以及電容C20使得表面聲 波濾波器4 0的輸入端阻抗匹配。電阻R1用以調整混波器 120的轉換增益（conversion gain)。將混波器12〇的差動 輸出電流轉換為單端電壓信號。At present, many RF modules (RF modules) use an ultra-high-frequency transceiver device, with a mid-band of tens to hundreds of megahertz, and almost use a surface acoustic wave filter saw as the cat rate option. Waves. At first glance, the current radio frequency integrated circuit (RF IC), the first down-conversion mixer mostly uses differential open-collector output, but the second down-conversion mostly uses single-ended input ^, resulting in signals other than double In addition to end-to-single-end, the connection effect between the middle and the surface acoustic wave filter must also be considered. Figure 1 shows a conventional conversion interface circuit. The front-end circuit 100 includes a low-noise amplifier 1 1 0, a mixer 丨 2 0, and its output terminals A, B are differential open collectors. Need A conversion interface circuit 50 converts the differential signal to a single-ended signal, which includes a resistor R1, an inductor L1, a capacitor C1, an inductor L10, a capacitor ° C10, and a capacitor C20. The conversion interface circuit 50 outputs a single-ended signal to a surface Input of sonic filter 40. Inductor L1 and capacitor C1 are tuned at the required mid-frequency band and provide 180-degree inverting output at the output terminals IA and IB. Combined with in-phase energy, input single-ended load, which is the conversion interface circuit The function of 50 is a current combiner. The inductor L1 0 is used to enter the VCC by the choke intermediate frequency (if) signal, and has another function to cooperate with the capacitor C20 as a matching circuit. The function of the capacitor C20 is Then suppress the signal interference generated by the intermediate frequency signal into the VCC. The capacitor cio is used for DC blocking. On the other hand, the capacitor C10 and capacitor C20 make the input impedance of the surface acoustic wave filter 40 match. Resistance R1 is used to adjust Wave conversion gain (conversion gain) 120 of The mixer 12〇 differential output current into a single-ended voltage signal.
0683-8295TWF(n);T-98;RLIU.ptd 第 4 頁 583846 五、發明說明（2) 調整第1圖的轉換介接電路50相當花費時間。調整匹 =路，電感L10、電容C2〇會影響電感u、電容π的調譜 頻率。因此，又必須調整電感L1、電容C1，同樣地， 電感L1〇、電容C20的匹配阻抗。所以必須反覆調整 電感L/0、電容C20、電感L1、電容C1，不容易匹配。 第2圖表示習知轉換介接電路。混波器丨2〇的輸出端 、=為差動開集極。轉換介接電路5〇將差動信號轉換到 單端信號，其包括電感L1、電感L2、電容C1、電阻R1()、 電容CIO、C20。轉換介接電路5〇輸出單端信號到表面聲波 濾波器40的輸入端。並聯電感L1、[2以及電容〇1調諧轉換 介接電路50在所需要的中頻段，並且在輸出端〗八、ib提供 180度反相輸出，結合同相能量，輸入單端負載。電容ci〇 是用以隔離直流，並且有另一功能是配合電阻R1 〇作為匹 配電路的一部份，使得表面聲波濾波器4〇的輸入端阻抗匹 配。電容C20作為直流隔離。 同樣地，調整第二圖的轉換介接電路也是必須反覆調 整匹配電路。 、口 以上兩種架構的電路走線都會影響電路轉換效率，以 及阻抗的匹配。特別是電感和電容的諧振頻率必須在中頻 段，任何寄生電容都會影響電流結合器，無法有效地將混 波器的反相輸出端以同相位的結合輸出，降低轉換效率。 為了有效匹配差動混波器，結合差動混波信號，必須提出 一具有匹配轉介混波器的超外差收發裝置。 有鑑於此，本發明提供一種超外差收發裝置，其包 0683-8295™(η);Τ-98;Ι^ΐυ.ρΐά0683-8295TWF (n); T-98; RLIU.ptd page 4 583846 V. Description of the invention (2) Adjusting the conversion interface circuit 50 in Fig. 1 takes considerable time. Adjusting the voltage = the inductor L10 and capacitor C20 will affect the frequency spectrum of inductor u and capacitor π. Therefore, it is necessary to adjust the inductance L1 and the capacitance C1 again. Similarly, the matching impedance of the inductance L10 and the capacitance C20. Therefore, it is necessary to adjust the inductor L / 0, capacitor C20, inductor L1, and capacitor C1 repeatedly, which is not easy to match. Fig. 2 shows a conventional switching interface circuit. The output end of the mixer 丨 2 is a differential open collector. The conversion interface circuit 50 converts the differential signal to a single-ended signal, which includes an inductor L1, an inductor L2, a capacitor C1, a resistor R1 (), and capacitors CIO and C20. The conversion interface circuit 50 outputs a single-ended signal to the input terminal of the surface acoustic wave filter 40. The shunt inductor L1, [2, and the capacitor 0 are tuned and converted. The interface circuit 50 is at the required mid-frequency band, and at the output terminal, the ib provides a 180-degree inverting output, which combines single-phase energy and inputs a single-ended load. Capacitor ci〇 is used to isolate DC, and has another function is to match resistor R1 〇 as a part of the matching circuit, so that the input impedance of surface acoustic wave filter 40 is matched. Capacitor C20 acts as DC isolation. Similarly, adjusting the conversion interface circuit of the second figure must also adjust the matching circuit repeatedly. The circuit routing of the above two architectures will affect the circuit conversion efficiency and impedance matching. In particular, the resonance frequency of the inductor and capacitor must be in the intermediate frequency band. Any parasitic capacitance will affect the current coupler, and it is not possible to effectively output the inverting output of the mixer with the same phase to reduce the conversion efficiency. In order to effectively match the differential mixer, combined with the differential mixed signal, it is necessary to propose a super-heterodyne transmitting / receiving device having a matched referential mixer. In view of this, the present invention provides a superheterodyne transmitting and receiving device, which includes 0683-8295 ™ (η); T-98; Ι ^ ΐυ.ρΐά